The unexpected royal Princess Charlotte bears a striking resemblance to in her birthday photos

Ahead of Princess Charlotte’s fourth birthday, the Duke and Duchess of Cambridge released some adorable photos of their daughter, taken on the grounds of Kensington Palace and at their Norfolk estate, Amner Hall.

Of course, it hasn’t taken long for the royal comparisons to start to see which member of the family Charlotte resembles most.

While the four-year-old undoubtedly bears a striking resemblance to her great-grandmother, Queen Elizabeth II, there’s another royal Charlotte is the spitting image of.

As pointed out by Rebecca English, a royal correspondent for the Daily Mail, the fourth in line to the throne looks very much like the late Queen Mother when she was young – then known as Lady Elizabeth Bowes-Lyon.

In images from her childhood, the resemblance between the Queen Mother and Charlotte now is, as English describes, “quite uncanny”.

Charlotte does also, of course, look very similar to the Queen when she was that age, particularly in the photos she is wearing a tartan skirt, with a grey cardigan.

In black and white photos of Her Majesty in the 1936 at the Royal Lodge on the Windsor Estate, a young Princess Elizabeth is wearing a tartan skirt and a knitted jumper, very similar to Charlotte’s outfit in the snaps taken by Kate Middleton.

While Charlotte is often likened to her mother, it’s clear the young royal looks very much like her father, Prince William.

As can be seen photographs of William at the same age as his daughter, Charlotte most certainly has the same cheeky grin as her father, as well as similar facial features.

There's no denying strong genes definitely run in the royal family, but Charlotte also seems to have very strong features from the Spencer family too.

She has regularly been compared to her late mother, Princess Diana, particularly in the photo the Cambridges released for Christmas.

In the snap, Charlotte looks particularly like Diana in one specific photo dating back to July 1970, when her grandmother was nine-years-old.

Both Charlotte and Diana have similar expressions on their faces, as well as being photographed at similar angles.

More notably, showing just how strong the Spencer family gene is, a few months back, Diana's niece, Lady Kitty Spencer, posted a photo of herself on Instagram from her first day of school, and is the spitting image of Charlotte.

Many fans flocked to the comments of the 27-year-old's post, comparing Kitty to Charlotte.

"Charlotte looks like you," one person said. "Those stunning Spencer genes."

Other followers' comments echoed similar sentiments.

Well, Charlotte certainly has won the genetic lottery with a combination of the royal family genes, Spencer family genes and the Middleton family genes.